This invention relates to a suspension assembly and particularly to an assembly designed to monitor critical movement of a vehicle frame and/or axle housing.
In a vehicle, conventional leaf springs are provided which serve to connect the vehicle rear axle housing to the vehicle frame. Occasionally, unequal loads are placed on the vehicle causing uneven loading of the respective leaf springs which in turn causes the vehicle frame to tilt from a desired plane. Such a situation frequently arises in trucks because of their load carrying function and more frequently in those trucks having a boom or derrick mounted thereon which presents an overhung load to the vehicle springs upon swinging the boom or derrick to a selected side.
Accordingly, it is known to provide a stabilizer assembly having a transverse torsion bar joined between two torque arms extending from the respective ends of the torsion bar. The torsion bar in turn is connected to the automobile frame with the free ends of the arms connected to the axle housing.
In operation of known assemblies an external force on a wheel through the leaf spring is transmitted along the axle housing to the junction of the arm and the axle housing and thus produces a torque about the longitudinal axis of the torsion bar. This torque produces a compensating force along the opposite arm so as to produce a similar vertical displacement on the opposite wheel relative to the frame. Accordingly, tilting of the frame from a desired plane is inhibited by such a compensating force. It can be seen that concurrent application of equal forces to the wheels and/or springs provides compensatory forces of a generally cancelling effect.
Problems have arisen in the use of such systems including a desire to have a suspension assembly which not only addresses the maintenance of the vehicle frame attitude, but also functions as an overload device to resist the displacement of the chassis during normal vehicle motion. Also, attempts have been made to negate forces produced along the axle housing during acceleration of the vehicle and transmitted to the suspension assembly which decrease its effectiveness. Such basic problems have been addressed by the use of relatively complex and expensive structures for attachment to the rear axle assembly and vehicle frame. Although somewhat effective in their operation, such structures having received limited acceptance.
A consideration in these assemblies, heretofore not particularly addressed, is the juncture formed at the connection of the rear axle housing and the leaf spring so as to join the axle housing to the vehicle frame. This juncture is of importance, as the movement of the rear axle, and more particularly, deflection of the normal curvature of the leaf spring is a critical indicator of the displacement between the vehicle frame and rear axle and is thus an ultimate indicator of any external forces which may effect a desired vehicle frame attitude and/or ride. Thus, means for providing a stabilizing device which is directly and concurrently responsive to the deflection of the leaf spring, as well as displacement of the axle housing is particularly warranted.
Known devices have not been enmeshed into this leaf spring/axle housing juncture, but have been displaced either vertically or laterally therefrom. Lateral displacement of the torque arm/axle housing juncture from the spring/axle housing juncture presents a distance along which forces can act and thus produced unwanted forces along the respective torque arms. Such unwanted and unnecessary forces inhibit the optimal functioning of known stabilizer apparatus.
Furthermore, many of the suspension assemblies fail to address the ride of the vehicle when in motion and, in some cases had to be disconnected from the frame when carrying a normal load during normal vehicle movement. Also, during a heavy load condition, the underlying leaf springs are normally stiffened which inhibits the smoothness of vehicle ride.
The present invention provides a means for coupling the forward end of each torque arm to the axle housing by use of a bracket particularly designed to be sandwiched between the rear leaf springs and the axle housing so as to be an effective barometer of spring deflection and axle housing movement. Furthermore, the invention provides means of resiliently mounting the end of the arm to the above bracket and to the vehicle frame which is effective to reduce any lateral strains and stress on the torque arms as well as acts as a supplementary shock absorber to dampen the displacement of the vehicle chassis.
Accordingly, it is a general object of this invention to provide a vehicle suspension assembly which will act to reduce tilting of the vehicle frame when presented with an overhung or an uneven load.
Another object of this invention is to provide an assembly, as aforesaid, which will improve the riding and driving characteristics of the vehicles in which it is installed.
A further object of this invention is to provide a suspension assembly, as aforesaid, having a pair of torque arms and torsion bar therein which is mounted to the vehicle frame and axle housing so as to be directly and concurrently responsive to the vehicle spring deflection and/or axle housing movement.
A particular object of this invention is to provide a suspension assembly, as aforesaid, having a pair of brackets therein, particularly designed to couple the front end of each torque arm to the vehicle spring/axle housing juncture.
Still another particular object of this invention is to provide a means of resiliently linking the ends of the respective torque arms to the vehicle frame and axle housing so as to be yieldable to vertical and lateral forces acting thereon.
Another object of this invention is to provide a suspension assembly, as aforesaid, which will inhibit the lateral movement between the vehicle frame and rear axle housing.
A still further object of this invention is to provide an assembly, as aforesaid, which can be used either with a suspension system employing leaf springs or employing coil or other type of springs.
Another object of this invention is to provide a suspension assembly, as aforesaid, which provides means for offsetting the effects of twisting displacements of the axle housing and unmatched vertical displacements of the vehicle frame.
Still another object of this invention is to provide a suspension assembly, as aforesaid, which is simple in construction, efficient in operation and inexpensive to manufacture and maintain.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein are set forth by way of illustration and example a preferred embodiment of this invention.